21485899 has 2 divisors, whose sum is σ = 21485900. Its totient is φ = 21485898.

The previous prime is 21485881. The next prime is 21485911. The reversal of 21485899 is 99858412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21485899 - 2⁷ = 21485771 is a prime.

It is not a weakly prime, because it can be changed into another prime (21485809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10742949 + 10742950.

It is an arithmetic number, because the mean of its divisors is an integer number (10742950).

Almost surely, 2^21485899 is an apocalyptic number.

21485899 is a deficient number, since it is larger than the sum of its proper divisors (1).

21485899 is an equidigital number, since it uses as much as digits as its factorization.

21485899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 46.

The square root of 21485899 is about 4635.2884484140. The cubic root of 21485899 is about 278.0040844422.

The spelling of 21485899 in words is "twenty-one million, four hundred eighty-five thousand, eight hundred ninety-nine".